Renée Zellweger pulls her hair into a low, messy ponytail for the premiere of My One And Only in New York on 18 August.Rihanna's quiff looks higher than ever as she arrives at LAX airport on 13 August.Mel B straightens her hair for the opening party of luxury resort Terranea in LA on 15 August.Britney Spears keeps her hair dry with a loose topknot while swimming with her kids at The Ritz-Carlton